Plasticizer effect on the ionic conductivity of PEO-based polymer electrolyte

The effects of plasticizer ethylene carbonate (EC) on the AC impedance spectra and the ionic conductivity are reported. With increasing of EC concentration the semicircle in high frequency disappears, and the slope of the straight line in low frequency decreases. The data obtained from impedance experiments can be explained using an equivalent circuit proposed. On the other hand, the room temperature conductivity increases with EC concentration because of the increase of the segmental flexibility of PEO. For lower EC concentration samples, the temperature dependence of conductivity in low temperature range follows Arrhenius type, but when EC concentration is larger than 20%, the temperature dependence of conductivity obeys the Vogel-Tamman-Fulcher (VTF) equation in all temperature ranges.

Impedance study of (PEO)(10)LiClO4-Al2O3 composite polymer electrolyte with blocking electrodes

A composite solid polymer electrolyte (SPE) of (PEO)(10)LiClO4-Al2O3 was prepared and Pt and stainless steel(SS) blocking electrodes were used for an impedance study. It was found that the semicircle in the high frequency range and the straight line in the low frequency range depend upon different blocking electrodes and polarization potentials applied in the experiments. In the equivalent circuit. two constant phase elements (CPE) have been used instead of the pure geometrical and double layer capacitances. respectively. A theoretical line calculated from their estimated values has a good correlation with the experiment data. Moreover. the equivalent circuit also can be used to explain the impedance properties of Pt and stainless steel (SS) blocking electrodes both in the high and the low frequency ranges. (C) 2001 Elsevier Science Ltd. All rights reserved.

Aberrant expression of X-linked genes RbAp46, Rsk4, and Cldn2 in breast cancer

The consequence of activation status or gain/loss of an X-chromosome in terms of the expression of tumor suppressor genes or oncogenes in breast cancer has not been clearly addressed. In this study, we investigated the activation status of the X-chromosomes in a panel of human breast cancer cell lines, human breast carcinoma, and adjacent mammary tissues and a panel of murine mammary epithelial sublines ranging from low to high invasive potentials. Results show that most human breast cancer cell lines were homozygous, but both benign cell lines were heterozygous for highly polymorphic X-loci (IDS and G6PD). On the other hand, 60% of human breast carcinoma cases were heterozygous for either IDS or G6PD markers. Investigation of the activation status of heterozygous cell lines revealed the presence of only one active X-chromosome, whereas most heterozygous human breast carcinoma cases had two active X-chromosomes. Furthermore, we determined whether or not an additional active X-chromosome affects expression levels of tumor suppressor genes and oncogenes. Reverse transcription-PCR data show high expression of putative tumor suppressor genes Rsk4 and RbAp46 in 47% and 79% of breast carcinoma cases, respectively, whereas Cldn2 was down-regulated in 52% of breast cancer cases compared with normal adjacent tissues. Consistent with mRNA expression, immunostaining for these proteins also showed a similar pattern. In conclusion, our data suggest that high expression of RbAp46 is likely to have a role in the development or progression of human breast cancer. The activation status of the X-chromosome may influence the expression levels of X-linked oncogenes or tumor suppressor genes.

Development of the East Asian summer monsoon: Evidence from the sediment record in the South China Sea since 8.5 Ma

128 samples from Ocean Drilling Program (ODP) Site 1143 in the southern South China Sea were analyzed for grain size, clay minerals, biogenic opal content and quartz in order to reconstruct changes in East Asian monsoon climate since 8.5 Ma. An abrupt change of terrigenous mass accumulation rate (MAR), clay mineral assemblage, median grain size and biogenic opal MAR about 5.2 Ma suggests that between 8.5-5.2 Ma the source of terrigenous sediment was mainly in the region of surface uplift and basaltic volcanism in southern Vietnam. A simple model of East Asian summer monsoon evolution was based on the clay/feldspar ratio, kaolinite/chlorite ratio and biogenic opal MAR. The summer monsoon has two periods of maximum strength at 8.5-7.6 Ma and 7.1-6.2 Ma. Subsequently, there was a relatively stable period at 6.2-3.5 Ma, continued intensification about 3.5-2.5 Ma, and gradually weakening after 2.5 Ma. Since I Ma the monsoon has intensified, with remarkable high-frequency and amplitude variability. Simultaneous increase in sedimentation rates at ODP Sites 1143, 1146 and 1148, as well as in MAR of terrigenous materials, quartz, feldspar and clay minerals at ODP Site 1143 at 3.5-2.5 Ma, may be the erosional response to both global climatic deterioration and the strengthening of the East Asian summer monsoon after about 3-4 Ma. (c) 2006 Elsevier B.V. All rights reserved.

Factors affecting the estimation of gas hydrate and free gas saturation

Attenuations of different types of gas hydrate cementation in fluid-saturated porous solids are discussed. The factors affecting estimation of gas hydrate and free gas saturation are analyzed. It is suggested that porosity of sediment, the P wave velocity model and methods of calculating elastic modulus are key factors in the estimation of gas hydrate and free gas saturations. Attenuation of gas hydrate-bearing sediment is closely related with the cementation types of gas hydrate. Negative anomalies of quality factors indicate that gas hydrate deposits away from grain as part of fluid. Positive anomalies of the quality factors indicate that gas hydrate contacts with solid and changes the elastic modulus of matrix. Low frequency velocity and high frequency velocity models are used to estimate gas hydrate and free gas saturation in the Blake Ridge area according to the well log data of the hole 995 in ODP leg 164. The gas hydrate saturation obtained by low frequency velocity is 10% similar to 20% of the pore space and free gas saturation is 0.5% similar to 1% of the pore space. The gas hydrate saturation obtained by high frequency velocity is 5% similar to 10% of the pore space and free gas saturation is 1% similar to 2% of the pore space.

25ka B.P.以来黑潮流域古环境演化对高频全球变化事件的响应

本文利用黑潮流域主流轴上的两个柱状沉积物岩芯MD05-2908以及PC-1为研究材料，在AMS14C测年的基础上，利用高分辨率的有机地球化学分析记录结合浮游有孔虫氧、碳同位素，恢复并重建了过去25,000 cal a BP以来黑潮流域古海洋环境演化的历史。以及表层海水生产力以及物质输送状况的演化历史。通过利用Uk’37古海水温度以及盐度指标恢复重建了过去25,000 cal a BP以来海洋表层海水温度、盐度；通过机碳、氮含量以及同位素变化、长链正构烷烃以及正构烷醇等指标重建了过去7000a B.P.以来的陆源物质输入历史；通过长链不饱和烯酮含量以及有机碳同位素指标恢复了过去7000a B.P.以来海水表层生产力的历史。此外，通过基于以上各种指标的环境信息与区域以及全球其它气候记录进行对比研究以及不同环境指标的时间系列分析，探讨了该区表层环流系统以及生产力的演化对于全球气候变化的响应，揭示了不同尺度的短周期高频率全球变化事件在黑潮流域的具体作用过程和响应机制。通过这些研究取得了以下的主要认识： 基于有机地球化学指标的古气候环境记录与黑潮流域已有的研究成果有很好的对应关系，从我们高分辨率的有机地球化学记录中可以识别出全新世黑潮强弱变化的几次明显的事件；25000a B.P.以来黑潮流域的环境变化与全球环境变化有着很好的对应性，黑潮强弱演化总体趋势与全球气候背景演化相一致，黑潮对高频气候变化事件的记录与全球记录具有同步性，这种同步性尤其体现在末次冰消期以来的气候快速高频振荡以及全新世以来的气候突变事件上。 全球性的高频气候事件对黑潮主体本身及黑潮流域的相邻区域的大气和海洋环流都具有重要的控制作用，这种控制作用主要通过副高、ITCZ以及季风三种气候要素之间相互关联、彼此影响造成的。具体表现为：太阳辐射量的减少导致热力差异减小，这种相对减小弱化了热带西太平洋的对流活动，造成了西太平洋副热带高压长期偏南、偏东，ITCZ平均北界位置偏南，降雨带长时间集中在南部地区，增强的降雨量提高了风化剥蚀以及沉积物向海洋搬运的能力，陆源物质供应量增加；同时，辐射量以及热力差的减小又与加强的东亚冬季风相联系，增强的冬季风导致了近底层“雾状层”物质的向海传输，物质传输效率增高。这种物源供应以及搬运量的双重增加导致了冲绳海槽流域物质通量的增加。 基于有机地球化学指标的海洋表层生产力的变化与陆源物质供应量以及黑潮流的强弱变化存在着对应关系，通常情况增加的海洋表层生产力对应着高的陆源物质输入以及相对较弱的黑潮。这种变化与东亚夏季风的以及冬季风的强弱都有很好的一致性。陆源物质的输入增加了表层营养物质的含量，导致生产力的勃发；陆源物质的输入增加又对应着减少的太阳辐射量，偏南的ITCZ北界位置以及副热带高压，这些对应于减弱的东亚夏季风（增强的东亚冬季风）。 黑潮流域的高沉积速率事件对应于减弱的黑潮强度和增加的ENSO频度，这些事件与上述的副热带高压、ITCZ位移和强弱的变化相一致。黑潮流域过去25000a B.P.以来南北温度的差异有冰期加大而全新世减小的趋势，但这种冰期与全新世的差异很小，我们认为末次盛冰期的时候黑潮主流轴没有移出冲绳黑潮，只是由于强度的减弱受陆架水体的影响有所加大。 黑潮流域很好的记录到了包括数千年尺度的D/O旋回周期到大气——海洋系统内部振荡所致的PDO、NAO等数十年尺度的高频振荡，说明黑潮流域对过去全球及区域环境变化事件有很好的响应。黑潮流域各古海洋指标所记录周期上的一致性说明这些环境因子控制机理上具有的一致性，即大背景上受太阳活动所引起的辐射量变化控制，局部的高频快速气候波动又受到局域性的气候因素如海气相互作用的放大影响。

Interannual horizontal heat advection in the surface mixed layer over the equatorial Pacific Ocean: assimilation versus TAO analysis

The interannual anomalies of horizontal heat advection in the surface mixed layer over the equatorial Pacific Ocean in an assimilation experiment are studied and compared with existing observational analyses. The assimilation builds upon a hindcast study that has produced a good simulation of the observed equatorial currents and optimizes the simulation of the Reynolds sea surface temperature (SST) data. The comparison suggests that the assimilation has improved the simulation of the interannual horizontal heat advection of the surface mixed layer significantly. During periods of interrupted current measurements, the assimilation is shown to produce more meaningful anomalies of the heat advection than the interpolation of the observational data does. The assimilation also shows that the eddy heat flux due to the correlation between high-frequency current and SST variations, which is largely overlooked by the existing observational analyses, is important for the interannual SST balance over the equatorial Pacific. The interannual horizontal heat advection anomalies are found to be sensitive to SST errors where oceanic currents are strong, which is a challenge for ENSO prediction. The study further suggests that the observational analyses of the tropical SST balance based on the TAO and the Reynolds SST data contain significant errors due to the large gradient errors in the Reynolds SST data, which are amplified into the advection anomalies by the large equatorial currents.

Representation of microscale ocean wavenumber spectrum correct to the second order

In this paper, the analytical representations of four wave source functions in high-frequency spectrum range are given on the basis of ocean wave theory and dimensional analysis, and the perturbation method is used to solve the governing equations of ocean wave high-frequency spectrum on the basis of the temporally stationary and locally homogeneous scale relations of microscale wave. The microscale ocean wavenumber spectrum correct to the second order has an explicit structure, its first order part represents the equilibrium between different source functions, and its second order part represents the contribution of microscale wave propagation.

Ocean wave imaging mechanism by imaging radar

Analytical representations of the high frequency spectra of ocean wave and its variation due to the variation of ocean surface current are derived from the wave-number spectrum balance equation. The ocean surface imaging formulation of real aperture radar (RAR) is given using electromagnetic wave backscattering theory of ocean surface and the modulations of ocean surface winds, currents and their variations to RAR are described. A general representation of the phase modulation induced by the ocean surface motion is derived according to standard synthetic aperture radar (SAR) imaging theory. The detectability of ocean current and sea bottom topography by imaging radar is discussed. The results constitute the theoretical basis for detecting ocean wave fields, ocean surface winds, ocean surface current fields, sea bottom topography, internal wave and so on.

Effects of winds, tides and storm surges on ocean surface waves in the Sea of Japan

Ocean surface waves are strongly forced by high wind conditions associated with winter storms in the Sea of Japan. They are also modulated by tides and storm surges. The effects of the variability in surface wind forcing, tides and storm surges on the waves are investigated using a wave model, a high-resolution atmospheric mesoscale model and a hydrodynamic ocean circulation model. Five month-long wave model simulations are inducted to examine the sensitivity of ocean waves to various wind forcing fields, tides and storm surges during January 1997. Compared with observed mean wave parameters, results indicate that the high frequency variability in the surface wind filed has very great effect on wave simulation. Tides and storm surges have a significant impact on the waves in nearshores of the Tsushima-kaihyo, but not for other regions in the Sea of Japan. High spatial and temporal resolution and good quality surface wind products will be crucial for the prediction of surface waves in the JES and other marginal seas, especially near the coastal regions.

Mitochondrial and chloroplast phylogeography of Picea crassifolia Kom. (Pinaceae) in the Qinghai-Tibetan Plateau and adjacent highlands

The disjunct distribution of forests in the Qinghai-Tibetan Plateau (QTP) and adjacent Helan Shan and Daqing Shan highlands provides an excellent model to examine vegetation shifts, glacial refugia and gene flow of key species in this complex landscape region in response to past climatic oscillations and human disturbance. In this study, we examined maternally inherited mitochondrial DNA (nad1 intron b/c and nad5 intron 1) and paternally inherited chloroplast DNA (trnC-trnD) sequence variation within a dominant forest species, Picea crassifolia Kom. We recovered nine mitotypes and two chlorotypes in a survey of 442 individuals from 32 populations sampled throughout the species' range. Significant mitochondrial DNA population subdivision was detected (G(ST) = 0.512; N-ST = 0.679), suggesting low levels of recurrent gene flow through seeds among populations and significant phylogeographical structure (N-ST > GST, P < 0.05). Plateau haplotypes differed in sequence from those in the adjacent highlands, suggesting a long period of allopatric fragmentation between the species in the two regions and the presence of independent refugia in each region during Quaternary glaciations. On the QTP platform, all but one of the disjunct populations surveyed were fixed for the same mitotype, while most populations at the plateau edge contained more than one haplotype with the mitotype that was fixed in plateau platform populations always present at high frequency. This distribution pattern suggests that present-day disjunct populations on the QTP platform experienced a common recolonization history. The same phylogeographical pattern, however, was not detected for paternally inherited chloroplast DNA haplotypes. Two chlorotypes were distributed throughout the range of the species with little geographical population differentiation (G(ST) = N-ST = 0.093). This provides evidence for highly efficient pollen-mediated gene flow among isolated forest patches, both within and between the QTP and adjacent highland populations. A lack of isolation to pollen-mediated gene flow between forests on the QTP and adjacent highlands is surprising given that the Tengger Desert has been a geographical barrier between these two regions for approximately the last 1.8 million years.

Response of chlorophyll fluorescence to dynamic light in three alpine species differing in plant architecture

A study was carried out to examine the effect of dynamic photosynthetically active photon flux density (PPFD) on photoinhibition and energy use in three herbaceous species, prostrate Saussurea superba, erect-leaved S. katochaete, and half-erect-leaved Gentiana straminea, from the Qinghai-Tibet Plateau. Chlorophyll fluorescence response was measured under each of three sets of high-low PPFD combinations: 1700-0, 1400-300, and 1200-500 mu mol m(-2) s(-1), illuminating in four dynamic frequencies: 1, 5, 15, and 60 cycles per 2 h. The total light exposure time was 2h and the integrated PPFD was the same in all treatments. The highest frequency of PPFD fluctuation resulted in the lowest photochemical activity, the highest level of non-photochemical quenching, and the greatest decrease of F-v/F-m (maximal photochemical efficiency of PSII). The 5 and 15 cycles per 2h treatments resulted in higher photochemical activity than the 1 cycle per 2h treatment. The 1700-0 PPFD combination led to the lowest photochemical activity and more serious photoinhibition in all species. S. superba usually exhibited the highest photochemical activity and CO2 uptake rate, the lowest reduction of F-v/F-m,F- and the smallest fraction of energy in thermal dissipation. With similar fractions of thermal dissipation, S. katochaete had relatively less photoinhibition than G. straminea owing to effective F-o quenching. The results suggest that high frequency of fluctuating PPFD generally results in photoinhibition, which is more serious under periods of irradiation with high light intensity. (c) 2005 Elsevier B.V. All rights reserved.

Phylogeography of the Qinghai-Tibetan Plateau endemic Juniperus przewalskii (Cupressaceae) inferred from chloroplast DNA sequence variation

The vegetation of the northeast Qinghai-Tibetan Plateau is dominated by alpine meadow and desert-steppe with sparse forests scattered within it. To obtain a better understanding of the phylogeography of one constituent species of the forests in this region, we examined chloroplast trnT-trnF and trnS-trnG sequence variation within Juniperus przewalskii, a key endemic tree species. Sequence data were obtained from 392 trees in 20 populations covering the entire distribution range of the species. Six cpDNA haplotypes were identified. Significant population subdivision was detected (G(ST) = 0.772, N-ST = 0.834), suggesting low levels of recurrent gene flow among populations and significant phylogeographic structure (N-ST > G(ST), P < 0.05). Eight of the nine disjunct populations surveyed on the high-elevation northeast plateau were fixed for a single haplotype (A), while the remaining, more westerly population, contained the same haplotype at high frequency together with two low frequency haplotypes (C and F). In contrast, most populations that occurred at lower altitudes at the plateau edge were fixed or nearly fixed for one of two haplotypes, A or E. However, two plateau edge populations had haplotype compositions different from the rest. In one, four haplotypes (A, B, D and E) were present at approximately equivalent frequencies, which might reflect a larger refugium in the area of this population during the last glacial period. Phylogenetic analysis indicated that the most widely distributed haplotype A is not ancestral to other haplotypes. The contrasting phylogeographic structures of the haplotype-rich plateau edge area and the almost haplotype-uniform plateau platform region indicate that the plateau platform was recolonized by J. przewalskii during the most recent postglacial period. This is supported by the findings of a nested clade analysis, which inferred that postglacial range expansion from the plateau edge followed by recent fragmentation is largely responsible for the present-day spatial distribution of cpDNA haplotypes within the species.

UHF RFID 射频前端及其编解码设计

射频识别（Radio Frequency Identification，RFID）技术，是一种利用射频通信实现的非接触式的数据采集和自动识别技术（以下通称RFID技术）。而超高频射频识别技术（Ultra High Frequency RFID，UHF RFID）具有识别距离远、识别准确率高、识别速度快、抗干扰能力强等特点而成为当前研发的热点。UHF RFID读写器的难点就在于射频前端电路和基带编解码的设计，它们设计的好坏直接决定了读写器的性能好坏。 本文首先通过介绍UHF RFID读写器射频前端设计的基本原理，采用射频通用收发模块进行射频前端设计的方法，给出了以ADF7020收发芯片为核心的UHF RFID读写器的射频前端的整体设计和具体的实现电路，设计了包括射频收发电路、射频前端匹配电路、滤波电路、环行器电路、功率放大电路等。 其次根据EPC Gen-2的协议标准进行了UHF RFID读写器的基带编码解码的仿真设计，然后开发了以FPGA为核心的完整的数字基带硬件电路，实际调试表明整个基带编解码软件在硬件基带PCB板上运行状况良好，并能对EPC Gen-2的协议标准的命令进行正确的编码解码。 最后通过研究学习软件无线电的理论和开发方法，把UHF　RFID读写器的射频前端分成射频模拟前端和射频数字前端，给出了一种基于软件无线电思想的UHF RFID射频数字前端设计模型，并借助于SIMULINK中的信号处理工具箱对构建的数字前端的进行仿真验证，仿真结果验证了用软件无线电实现UHF RFID数字前端的可行性。

地震数据波动方程反演方法研究

Geophysical inversion is a theory that transforms the observation data into corresponding geophysical models. The goal of seismic inversion is not only wave velocity models, but also the fine structures and dynamic process of interior of the earth, expanding to more parameters such as density, aeolotropism, viscosity and so on. As is known to all, Inversion theory is divided to linear and non-linear inversion theories. In rencent 40 years linear inversion theory has formed into a complete and systematic theory and found extensive applications in practice. While there are still many urgent problems to be solved in non-linear inversion theory and practice. Based on wave equation, this dissertation has been mainly involved in the theoretical research of several non-linear inversion methods: waveform inversion, traveltime inversion and the joint inversion about two methods. The objective of gradient waveform inversion is to find a geologic model, thus synthetic seismograms generated by this geologic model are best fitted to observed seismograms. Contrasting with other inverse methods, waveform inversion uses all characteristics of waveform and has high resolution capacity. But waveform inversion is an interface by interface method. An artificial parameter limit should be provided in each inversion iteration. In addition, waveform information will tend to get stuck in local minima if the starting model is too far from the actual model. Based on velocity scanning in traditional seismic data processing, a layer-by-layer waveform inversion method is developed in this dissertation to deal with weaknesses of waveform inversion. Wave equation is used to calculate the traveltime and derivative (perturbation of traveltime with respect to velocity) in wave-equation traveltime inversion (WT). Unlike traditional ray-based travetime inversion, WT has many advantages. No ray tracing or traveltime picking and no high frequency assumption is necessary and good result can be got while starting model is far from real model. But, comparing with waveform inversion, WT has low resolution. Waveform inversion and WT have complementary advantages and similar algorithm, which proves that the joint inversion is a better inversion method. And another key point which this dissertation emphasizes is how to give fullest play to their complementary advantages on the premise of no increase of storage spaces and amount of calculation. Numerical tests are implemented to prove the feasibility of inversion methods mentioned above in this dissertation. Especially for gradient waveform inversion, field data are inversed. This field data are acquired by our group in Wali park and Shunyi district. Real data processing shows there are many problems for waveform inversion to deal with real data. The matching of synthetic seismograms with observed seismograms and noise cancellation are two primary problems. In conclusion, on the foundation of the former experiences, this dissertation has implemented waveform inversions on the basis of acoustic wave equation and elastic wave equation, traveltime inversion on the basis of acoustic wave equation and traditional combined waveform traveltime inversion. Besides the traditional analysis of inversion theory, there are two innovations: layer by layer inversion of seimic reflection data inversion and rapid method for acoustic wave-equation joint inversion.